Sydney Roosters coach Trent Robinson says star player Mitchell Pearce apologised to him after a video showing him forcing himself onto a female partygoer and simulating sex with a dog emerged last night.

Robinson said the behaviour was "unacceptable" and promised the club would take action after "going through" the incident, adding that the club "can't accept that and we won't".

"The behaviour was unacceptable. We understand that," Robinson said at a press conference. "Over the next couple of days we will come to a conclusion with the NRL."

He said axing the incumbent NSW five-eighth was something they were considering and that Pearce had apologised to him and the playing group.

The Roosters announced earlier today that they have stood the premiership captain down from all training commitments pending an internal investigation, adding that it is working closely with the NRL Integrity Unit.

Pearce may also be banned him from travelling to England next month for the World Club challenge, the Daily Telegraph reports.

The vile act was captured on a mobile phone by a partygoer revealing the New South Wales State of Origin player allegedly making advances toward a woman in a bedroom, in a story broken by 7 News.

"I'm a lesbian," the woman says, rejecting Pearce's gesture.

Mitchell Pearce was filmed allegedly trying to kiss a woman at a house party on Australia Day. Photo: 7 News

While slurring his words, he can be seen turning his attention toward a dog and stimulating a lewd act upon the Maltese terrier.

"I don't have a sexuality" before picking up the small white dog and telling her "I'll f***k that dog...I don't give a s***t", Pearce says.

Pearce was filmed allegedly simulating a sexual act with a dog before being asked to leave. Photo: 7 News

The woman grabs the dog off of Pearce, accusing him of urinating on her couch.

“I want to f*** your dog and I don’t even care,” Pearce replies.

“I care, you have peed on my couch, you have peed on yourself, get the f*** out,” the woman tells him.

“That’s the last straw.”

Eventually, the rugby league player's friends escort him off the premises.

GALLERY: Click through to see the NRL's rap sheet after a long list of bad boy problems.

The entire episode was bought by The Daily Telegraph for $40,000 and Channel Nine paying $20,000 for the footage.

Twitter users have criticised the 26-year-old's actions saying it is a "disgrace".

Mitchell Pearce is a disgrace. I always give sports stars the benefit of the doubt, but his actions are disgusting. #NRL

RSPCA NSW Chief Inspector David O'Shannessy said the organisation is appalled by Pearce's actions.

"RSPCA NSW is appalled by footage showing NRL player Mitchell Pearce engaging in a lewd act with a dog on the night of January 26/27," the statement read adding they are investigating the situation.

The Sydney Roosters said in a statement they were aware of an incident involving Pearce and had informed the NRL's Integrity Unit and would commence its own investigation.

"The Club will conduct an internal investigation and will be making no further comment at this time," the club's statement said.

A statement from the NRL said it had asked the club for a report into the incident.

"The Integrity Unit will work with the Roosters to ensure the matter is dealt with appropriately," a spokesman said.

Pearce reportedly continued to party after his team mates went home. Source: AAP

It is not the first incident the son of former Test Australian test player Wayne Pearce has been reviewed by the Integrity Unit for off-field behaviour.

In 2014 he was suspended and fined $20,000 for the "yellow dress" incident in which police evicted him from a Sydney nightclub after an "inappropriate interaction" with a woman.

The incident was recorded on the King Cross nightclub's CCTV cameras.

The incident recalls a similarly depraved act in which Cronulla Shark and former Rooster Todd Carney was photographed in 2014 urinating into his own mouth, ending his career in the English Super League.